Tracking issue for experimental "args" feature

[taiki-e]

This issue tracks the experimental "args" feature.

Enable semihosting::experimental::env::args.

Open issues

• This has APIs somewhat different from those of the standard library.
  The function has const generics that specify the size of the internal buffer.
  

  semihosting/src/experimental/env.rs

  Lines 12 to 13 in 1b82359

  	/// Returns the arguments that this program was started with.
  	pub fn args<const BUF_SIZE: usize>() -> io::Result<Args<BUF_SIZE>> {

  
  The iterator is implemented only for reference since it returns Result<&str>.
  

  semihosting/src/experimental/env.rs

  Lines 17 to 18 in 1b82359

  	#[allow(clippy::copy_iterator)] // TODO
  	impl<'a, const BUF_SIZE: usize> Iterator for &'a Args<BUF_SIZE> {

TODO: write more on open issues